Saying the opening takbir quietly does not require sajda al-sahw

Question

The imam did not say the takbir al-tahrima (opening takbir) aloud — others did not hear it — while he said the other takbirs aloud. Is sajda al-sahw wajib in that case or not? Also, if sajda al-sahw was not wajib on the imam but he performed it anyway, is the prayer valid or not? A certain religious scholar says that the imam may perform sajda al-sahw even for omitting mustahabb acts in the prayer, and no harm will come to the prayer. Is this correct?

Answer

Saying the takbirs quietly does not make sajda al-sahw wajib; omitting a mustahabb does not make sajda al-sahw wajib. And if he performed sajda al-sahw under the assumption that it had become wajib, even then the prayer did not become fasid (invalid)

Source: Fatawa Mahmudiyya

Preview. The full text opens with JavaScript enabled.